Method of gas plating



1962 E. R BREINING ETAL 3,049,799

METHOD OF GAS PLATING 4 Sheets-Sheet 1 Filed July 28, 1958 v vvww 0 INVENTORS fZMER ROBRr BREIN/IVG JOHN R. u/fl/rAcRE ATTORNE VS 1962 E. R. BREINING ETAL 3,049,799

METHOD OF GAS PLATING 4 Sheets-Sheet 2 Filed July 28, 1958 m mm RE mam Wm mm a n 0W 0 n n MMY H 1962 E. R. BREINING ETAL 3,049,799

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METHOD OF GAS PLATING Filed July 28, 1958 4 Sheets-Sheet 4 INVENTORS EIMER ROBERT EFF/MING JOHN R. WHITACRE A TTORNEIS United States Patent 3,049,799 METHOD OF GAS PLATING Elmer Robert Breining and John R. Whitacre, Dayton,

Ohio, assignors, by mesne assignments, to Union Carbide Corporation, New York, N.Y., a corporation of New York Filed July 28, 1958, Ser. No. 751,395 4 Claims. (Cl. 29-420) This invention relates to the metallizing of a confined body of individual particles or fragments by gas plating and to articles produced thereby. More particularly the invention relates to the provision within the interstices of a confined body formed by a loose mass of fragments, particles or the like, of metal deposited from heat decomposable gaseous metal bearing compounds, the deposit having as a primary function the formation of a metallic network which extends through the confined body and retains the particles or fragments together.

The invention particularly contemplates a method of providing a gas-plated metal deposit as a network extending through a body of particles, which particles may be hollow or solid, and comprised of glass, metal, clay, the carbides such as silicon carbide, and resin materials, or mixtures of such components. Preferably to secure a high strength to weight ratio in the product the particles are hollow and small-but suificiently large to permit ready permeation of the interstices, defined by the adjacent particles of the body, by the plating gas.

:It is particularly contemplated by the invention to provide a gas plated product which is readily contoured to a predetermined shape, which has a good strength to weight ratio, low elongation and good compression characteristics and which is resistant to corrosive attack.

The invention will be more fully understood by reference to the following detailed description and accompanying drawings wherein:

FIGURE 1 is a perspective view of a gas plated product in accordance with the invention;

FIGURE 2 is a transverse sectional view of the prodnot of FIGURE 1;

FIGURE 3 is a representation of a photomicrograph of a portion of a product such as that illustrated in FIGURES 1 and 2;

FIGURE 4 is a view schematically illustrating apparatus useful in the practice of the method of invention;

FIGURE 5 is a fragmentary view illustrating one phase of the method of invention;

FIGURE 6 is a perspective view of a tubular product illustrating a further modification of the invention;

FIGURE 7 is a transverse sectional view of the prodnot of FIGURE 6;

FIGURE 8 illustrates a step in the formation of the product of FIGURES 6 and 7;

FIGURE 9 is a View illustrating another apparatus set up useful in the practice of the invention;

FIGURE 10 is a perspective view illustrating another modification of the invention in which the shape of the product is substantially rectangular;

FIGURE 11 is a view similar to that of FIGURE 10 but illustrating the product provided with opposing plates; and

FIGURE 12 is a view particularly illustrating a prodnot having various contours formed in accordance with the teachings of the invention.

Referring to the drawings, and first particularly to FIGURES 1-3, inclusive, the numeral 1 generally designates a solid rod having an outer skin 2 and a mass of fragments 3 retained together by metal deposited from the gaseous state and indicated at 4 (-FIGURE 3).

The term fragments as used herein is intended to indicate particles, pellets, marbles, and so forth, and

shapes which when loosely packed in contacting relation define a body through which interstices exist between the fragments. Such interstices are indicated at 5 in FIG- URE 3.

Referring now to FIGURE 4 and the apparatus in which a shaped article, such as that shown in FIGURE 1, is formed, the numeral 7 denotes a glass tube having slightly narrowed end portions 8, 9. Surrounding the tube in close contacting relationship therewith is a pipe 10, around which there is wrapped electrical insulating material 11. Supported on the electrical insulating material 11 is an induction heating winding 12 having leads I3, 14 providing power to the winding.

One narrowed end portion 9 of the tube 7 is provided initially with a mass of glass fibers and the tube is then filled with aggregates indicated at 3, and which in the present instance may be considered as fine hollow spherulitized clay fibers of about 20 mesh. The tube 7 is suitably substantially completely filled with the clay particles, and then the second end of the tube is closed with a mass of glass fibers 17.

The tube end 9 is provided with a T connector 18 having an inlet 19 from a flow meter 20. The flow meter 20 is connected through conduit 21 and shut-off valve 22 to a vaporizer indicated generally at 23 and having a supply of liquid carbonyl designated 24.

A nozzle 25 is arranged to provide a hot air blast over the vaporizer 23 and to create a pressure of nickel carbonyl within the vaporizer. This pressure is indicated by the gauge at 2'6; and 27 designates a filling valve for the vaporizer.

The second end of the T connector, indicated at $8, is connected to a flow meter 29. Flow meter 29 communicates through a conduit 30 with a carbon dioxide cylinder designated 33, the cylinder itself being provided with a gauge and the pressure reduction valve, the latter being designated at 31, 32.

Example I In the practice of the method of the invention in one experiment the vaporizer was brought to a temperature of approximately F., and the gauge then indicated a pressure of about 8 pounds per square inch. The induction heater was turned on and the specimen heated to approximately 350 F. Nickel carbonyl was then introduced at a flow meter of about 9 cubic centimeters per minute in vapor form. Carbon dioxide was (flowed through T-connector 18 at a rate of about .025 cubic feet per minute. This combined gas stream was then flowed through the tube 7 for a period of about 2% hours. At the end of this period the glass tube was removed from the apparatus and the tube broken to procure the specimen, that is, the metallized body. The gases permeate the interstices and decompose to provide metal on the particles. This metal is substantially in the form of a continuous network extending through the body of the particles.

Initially a deposit of metal is built up as designated at 2 in FIGURE 5 around the inner wall of the tube and between the tube and the body of the loosely packed fragments. T his is for the reason that the heat as applied is somewhat greater at the surface of the glass and that the clay particles themselves tend to be poor heat conductors. However, the layer 2 of FIGURE 5, which forms the ultimate skin of the product, as clearly shown in FIGURE 2, facilitates heat conduction. In many instances such a layer may itself be initially formed either by a gas plating procedure or other procedure to aid heat conduction to the fragments themselves.

In the specific experiment to which reference has been made the deposit of metal was about four times the weight of that of the spherules employed. A tensile scribed above, having a diameter of approximately 0.455

inch, plus or minus 0.003 inch, and a length of about 8 inches, was 5.75 grams per lineal inch. This is comparable to aluminum.

Example 11 A specific procedure in the manner described above when heat treated at about 700 F. for 4 hours and then cooled, exhibited a tensile strength of about 9,000 pounds per square inch at an elongation of about 3.3 percent.

As illustrative of the conditions suitable for effecting the above noted procedure of Example I, the following test data are presented:

No Temp F NI(CO)4, 002, Time,

cc./min. c.f.m. hrs.

Referring now to FIGURES 6, 7 and 8, there is shown therein a tubular article and the method of producing it. Referring to FIGURE 6 initially the numeral 35 designates the tubular article generally, while the skin of metal on the outer surface of the body is indicated at 36. The numeral 37 designates the fragments and the numeral 38 indicates the metal deposited from the gaseous state on to the fragments.

A core opening is indicated at 39. This core opening is formed as illustrated in FIGURE 8 by providing within the glass tube 7 at the start of the operation an aluminum rod 40 around which the fragments 37 are positioned. The glass tube 7 is then, with the aluminum rod in position, placed in the apparatus as indicated in FIGURE 4 and the metallizing is effected in the same manner.

On completion of the metallizing operation, the cooling of the tube, and the removal of the tube from the apparatus, the aluminum rod 40 is removed from the body. This is suitably effected by first breaking the glass to expose the body itself.

The specimen was then etched in sodium hydroxide, a concentration of about percent at 140 F. until the aluminum tubing was completely etched away.

The exterior skin of the resultant product, designated generally by the numeral '36, had a fine shiny appearance and a coating of the metal extended over the inner wall bounding the opening 39.

Rectangular samples or samples of square cross-section may be also produced in accordance with the invention as illustrated in connection with FIGURE 10, wherein 51 generally denotes the structure, 52 indicates the skin around the body, 53 denotes the particles and 54 designates the metal on the particles.

Further such a structure as illustrated in FIGURE 11 at 55 may have plates or other supporting material secured to opposite faces thereof, for example, the opposite faces may be gas plated to provide the relatively thick plates, or in a given instance plates might be attached by welding.

The structures indicated in the preceding figures, that is the FIGURES l, 6 and 10, may also be produced by the apparatus indicated in FIGURE 9. As shown the numeral 41 designates a container having a quantity of oil 42 filling the container to a suitable level. This container is provided on hot plates 43 in order to effect heating of the oil. A tube 44 having an inlet 45 and an outlet 46 is provided at 47 and 48 at the respective inlets and outlets with a quantity of fiber glass. Particles 49 such as already described fill the narrowed portion 50 of the tube. The tube and the fragments or particles are heated by the oil and the mixture of the nickel carbonyl or other plating gas and carbon dioxide or other inert gas are flowed to the particles through the mass of glass fibers, the decomposed gases flowing to the exhaust at 48. An interlacing or network of metal is provided over the fragments as previously described. Upon removal from the oil bath the tube 44 is cooled and broken to expose the metallized body of fragments. In this instance also a skin forms around the tube wall and accordingly the metal network and fragments are enclosed by a skin.

The tube already described as container for the fragments may be in any desirable form and if the particles employed are of sufliciently small size they will conform readily to the contour of the container or form. Thus as indicated in FIGURE 12. a very irregular shape may be produced accurately.

In FIGURE 12 the numeral 56 designates a rigid structure having a skin 57, fragments 58 and metal 59 over the fragments. The numeral 60 designates a contoured outer surface, an accurate reproduction of the form employed.

It is to be noted in connection with the foregoing description that the product of the operation, upon removal from the glass tube, is smooth and is a mirror-like surface. However, it is to be understood that it is not necessary to employ a form of glass, but other forms such as ceramic, hard rubber, or any material which will appropriately withstand the heat, may be utilized.

Also, it is to be noted that the network of metal rigidly .bonds together the fragments.

The product is useful in structural as well as ornamental applications, and since its physical characteristics closely approach those of aluminum metal, it may be substituted for aluminum metal in many applications, such as in airplane structure parts.

Attention is also called particularly to FIGURE 3 which is a representation of a photomicrograph of a product as illustrated in FIGURE 1. It is to be noted that not all of the interstices between the spherulitized particles are filled with metal, but that sufficient metal is present to bridge most of the gaps and to create a rigid light weight structure.

In addition to nickel other carbonyls, such as the hexacarbonyls, chromium, and the pentacarbonyls of iron, may be employed in the practice of the invention. Particularly it is to be noted that the gas plated metal, being of a high purity, tends to resist corrosion. Further, where low softening point materials, such as some plastics, are employed the temperature utilized to effect the deposition of the metal, in the case of nickel carbonyl, may be considerably lowered, for example, to about 230 F. Thus, for example, the metallizing of resinous material, such as methyl methacrylate, is practical.

Further, glass spherules, hollow or solid, may be employed to provide a structure having high compression strength and low compressibility.

Where desired metal fragments may form the inner core and the metal might even be of nickel fragments i or nickel powder, to provide an integral structure of one" metal, but formed with voids as indicated in FIGURE of the drawings. It will be understood that this invention is suscepti to modification in order to adapt it to different us" and conditions and accordingly, it is desired to cor hend such modifications within this invention as may fall within the scope of the appended claims.

What is claimed is:

1. The process which comprises providing a body of loosely packed contacting fragments within a container such that the body takes the shape of said container and the fragments define interstices between themselves, said fragments being hollow, spherulitized and of low heat conductivity, heating the container to thereby transmit heat to the fragments, permeating the body with a heat decomposable metal bearing gas whereby metal deposits from the gas initially at a greater rate on the wall portion of the container than in the body of the fragments to cause further heating of the fragments through the deposited metal, continuing the permeation of the body with the gas to provide a network of deposited metal throughout the body thereby binding the fragments by said deposited metal and inclosing spacings between the fragments, and thereafter removing the container from the metallized body of fragments.

2. The process of binding a mass of solid particles together, which comprises providing a body of loosely packed contacting solid particles within a container and wherein said body takes the shape of said container and the particles define interstices between themselves, said particles being of low heat conductivity, heating the container to thereby transmit heat to said particles, permeating the body with a heat-decomposable metal hearing gas whereby metal deposits from the gas initially at a greater rate on the wall portion of the container than in the body of said particles to cause further heating of the particles through the deposited metal, continuing the permeation of the body with the gas to provide a network of deposited metal throughout the body thereby binding the particles by said deposited metal and inclosing spacings between the particles, and thereafter removing the container from the metallized body of particles.

3. The process of binding a mass of solid particles together, which comprises providing a body of loosely packed contacting solid particles within a container and wherein said body takes the shape of said container and the particles define interstices between themselves, said particles being hollow and of low heat conductivity, heating the container to thereby transmit heat to said particles, permeating the body with a heat-decomposable metal bearing gas whereby metal deposits from the gas initially at a greater rate on the wall portion of the container than in the body of the said particles to cause further heating of the particles through the deposited metal, continuing the permeation of the body with the gas to provide a network of deposited metal throughout the body thereby binding the particles by said deposited metal and inclosing spacings between the particles, and thereafter removing the container.

4. The process of binding a mass of solid particles together, which comprises providing a body of loosely packed contacting solid particles within a container and wherein said body takes the shape of said container and the particles define interstices between themselves, said particles being of low heat conductivity, heating the container to thereby transmit heat to said particles, permeating the body with a heat-decomposable metal bearing gas whereby metal deposits from the gas initially at a greater rate on the wall portion of the container than in the body of said particles to cause further heating of the particles through the deposited metal, continuing the permeation of the body with the gas to provide a network of deposited metal throughout the body thereby binding the particles by said deposited metal and inclosing spacings between the particles, and thereafter removing the container from the metallized body of particles, said body of particles being heated to a temperature of between about 270 400 F. for permeating the body with heat-decomposable metal bearing gas.

References Cited in the file of this patent UNITED STATES PATENTS 1,125,161 Page Jan. 19, 1915 1,315,859 Pfanstiehl Sept. 9, 1919 1,547,836 Steenstrup July 28, 1925 2,289,897 Balke July 14, 1942 2,359,970 Clark Oct. 10, 1944 2,406,345 Brennan Aug. 27, 1946 2,616,165 Brennan Nov. 4, 1952 2,724,663 Bond Nov. 22, 1955 2,731,365 Weinrich Jan. 17, 1956 2,767,289 Robinson Oct. 16, 1956 2,862,783 Drummond Dec. 2, 1958 2,872,342 Nack Feb. 3, 1959 2,888,375 Drummond May 26, 1959 2,905,573 Marvin Sept. 22, 1959 2,934,820 Novak May 3, 1960 

1. THE PROCESS WHICH COMPRISES PROVIDING A BODY OF LOOSELY PACKED CONTACTING FRAGMENTS WITHIN A CONTAINER SUCH THAT THE BODY TAKES THE SHAPE OF SAID CONTAINER AND THE FRAGMENTS DEFINE INTERSTICES BETWEEN THEMSELVES, SAID FRAGMENTS BEING HOLLOW, SPHERULITIZED AND OF LOW HEAT CONDUCTIVITY, HEATING THE CONTAINER TO THEREBY TRANSMIT HEAT TO THE FRAGMENTS, PERMEATING THE BODY WITH A HEAT DECOMPOSABLE METAL BEARING GAS WHEREBY METAL DEPOSITS FROM THE GAS INITIALLY AT A GREATERRATE ON THE WALL PORTION OF THE CONTAINER THAN IN THE BODY OF THE FRAGMENTS TO CAUSE FURTHER HEATING OF THE FRAGMENTS THROUGH THE DEPOSITED METAL, CONTINUING THE PERMEATION OF THE BODY 